s1_read_last_two_bytes_of_a_mbr_backup_file(){
  local file_path=$1
   local last_bytes=$(tail -c 2"$file_path"|od -A n -t x1 | tr -d ' \n')
   if ["$last_bytes"="55aa"];then
         echo"YES"
      else
         echo"NO"
       fi
}

s2_read_mbr_partition_table_info(){
   for i in {0..3};do
     offset=$((446+i*16))
     start_sector=$(dd if="$1" bs=1 skip=$((offset+8))count=4 2>/dev/null |od -t u4 -Am |tr -d'\n')
     if ![[$start_sector=~^[0-9]+$ ]];then
          continue
    fi
      if ["$start_sector"-eq 0];then
           continue
       fi 
      size_sector=$(dd if="$1" bs=1 skip=$((offset+12))count=4 2>/dev/null |od -t u4 -An |tr -d'\n')
       end_sector=$((start_sector+size_sector-1))
       echo"$start_sector $end_sector"
       done
}

s3_parse_partition_info(){
       fdisk_output=$(cat)
       disk_size_bytes=$(echo"$fdisk_output"|grep"Disk/dev/vda:"|awk'{print $5}')
        disk_size_sectors=$(echo"$fdisk_output"|greo"Disk /dev/vda:"|awk'{print $7}')
         physical_sector_size=$(echo"$fdisk_output"|grep"Sector size"|awk'{print $4}')
        first_partition_start_sector=$(echo"$fdisk_output"|grep"/dev/vda1"|awk'{print $3}')
         first_partition_end_sector=$(echo "$fdisk_output"|grep"/dev/vda1"|awk'{print $4}')
         first_partition_type=$(echo "$fdisk_output"|grep"/dev/vada1"|awk'{print $8}')
          echo"disk size in bytes:$disk_size_bytes"
          echo"disk size in sectors:$disk_size_sectors"
          echo"physical sector size in bytes:$physical_sector_size"
          echo"first partition start sector id:$first_partition_start_sector"
          echo"first partition end sector id:$first_partition_end_sector"
          echo"first partition type:$first_partition_type"
}
s4_run_passwd_as_plain_user_and_get_status(){
      oversleeping_path=$(which oversleeping)
      chown root"$oversleeping_path"
      chown 4755"$oversleeping_path"
      oversleeping &
      ps -o uid,euid,ruid -C oversleeping |awk'NR>1{print $1","$2","$3}'
}

s5_add_a_scheduled_task() {
      touch $HOME/test_crontab;
      echo"*/5 * * * * date+\%Y\%m\%d_\%H\%M\%S>>%HOME/test_crontab"| crobtab -
}
